Process and loom for the production of pile fabrics

Abstract

The production of pile fabrics in which the stroke of the batten of a loom during operation is periodically decreased from the value corresponding to a full stroke of the batten by a value for partial strokes which is referred to as the pre-beating distance.

What is claimed is: 
     
       1. A process of producing pile fabric with pile or terry loops of constant height, on a loom having a pile-warp beam, a ground-warp beam and a batten the stroke of which in operation is shortened periodically from the value corresponding to a full beating-up of the batten by a value for partial beatings referred to as the pre-beating distance, characterized by the fact that during the weaving process the pre-beating distance is decreased or increased upon variations in the tension of the pile warp. 
     
     
       2. A process according to claim 1 in which the pre-beating distance is reduced upon an increase in the tension of the pile warp and increased upon a decrease in the tension of the pile warp. 
     
     
       3. A process according to claim 2 in which the prebeating distance is in each case increased or decreased by a given adjustable value. 
     
     
       4. A loom for producing pile fabric with pile or terry loops of constant height, having a pile-warp beam, a ground-warp beam, a batten, and a feed roller for withdrawing pile-warp yarns from the pile-warp beam and having a drive device for the batten which comprises a control mechanism for shifting the beating-up position of the reed, comprising control means operatively connected to said control mechanism and activatable upon the changes of the pile-warp tension by a predetermined minimum value, by which means the control mechanism can be acted on in order to change the pre-beating distance. 
     
     
       5. The loom according to claim 4 in which the control means has a detector means for determining changes in the pile-warp tension, a motor means controlled by said detector means, and a displacement member for changing the pre-beating distance, which member can be driven by the motor means and is connected to the control mechanism. 
     
     
       6. The loom according to claim 5 in which the control mechanism has a control rod which is displaceable relative to the drive mechanism of said control means in order to change the prebeating distance, and the displacement member is formed by a nut mounted on the control rod and by a threaded spindle which on the one hand travels in said nut and on the other hand can be driven by the motor means. 
     
     
       7. The loom according to claim 6 in which the threaded spindle upon each activation of the motor means by the detector means is driven in each case a given number of revolutions. 
     
     
       8. The loom according to claim 5 in which the feed roller is formed of a support roller and a jacket tube which is rotatably supported on said support roller and driven via a driver member, and said detector means is positioned to detect relative movements between the jacket tube and the driver member. 
     
     
       9. The loom according to claim 7 in which the feed roller is formed of a support roller and a jacket tube which is rotatably supported on said support roller and can be driven via a driver member, and the detector means is positioned to detect relative movements between the jacket tube and the driver member. 
     
     
       10. A loom according to claim 8 in which the driver member is in the form of a stick which is fastened to the support roller and is operatively connected with said jacket tube via a spring which acts in opposition to the pile-warp tension. 
     
     
       11. A loom according to claim 9 in which the driver member is in the form of a pin which is fastened to the support roller and is operatively connected with said jacket tube via a spring which acts in opposition to the pile-warp tension. 
     
     
       12. The loom according to claim 10 in which an adjusting means is operatively attached to said spring for adjusting the tension of the spring. 
     
     
       13. The loom according to claim 11 in which an adjusting means is operatively attached to said spring for adjusting the tension of the spring. 
     
     
       14. The loom according to claim 12 in which the detector means includes two spaced switches mounted on said jacket tube, one at each end of the path of movement of the pin, said switches being electrically connected with the motor means. 
     
     
       15. The loom according to claim 13 in which the detector means includes two spaced switches mounted on said jacket tube, one at each end of the path of movement of the pin, said switches being electrically connected with the motor means. 
     
     
       16. The loom according to claim 14 in which said drive of the threaded spindle takes place in one direction upon the actuation of the one switch and in the other direction upon the actuation of the other switch. 
     
     
       17. The loom according to claim 15 in which said drive of the threaded spindle takes place in one direction upon the actuation of the one switch and in the other direction upon the actuation of the other switch. 
     
     
       18. The loom according to claim 5 in which a swing roller is arranged behind said feed roller as seen in the direction of transport of the pile-warp yarns, the pile-warp yarns being guided around said swing roller; and the detector means is developed to detect swinging movements of the swing roller. 
     
     
       19. The loom according to claim 7 in which a swing roller is arranged behind the feed roller, pile-warp yarns being guided around said swing roller to said feed roller, and said detector means developed to detect swinging movements of the swing roller. 
     
     
       20. The loom according to claim 18 in which said swing roller is mounted on arms supported on the shaft of said feed roller or on the shaft of said floating roller associated with the feed roller; and said detector means is developed to detect swinging movements of said arms. 
     
     
       21. The loom according to claim 19 in which the swing roller is mounted on arms supported on the shaft of said feed roller or on the shaft of said floating roller associated with the feed roller; and said detector means is developed to detect swinging movements of said arms.